Frequently Asked Questions

For more information, visit the Duo Documentation page

Authentication is the act of an identity verifying that they are who they say they are. A "factor" is a type of authentication method. It is commonly something that a user knows, possesses, or is as in biometrics or location. Multi-Factor authentication will utilize a combination of factors to verify the identity of a user. SDSU is using Duo Security as a multi-factor authentication solution.

For setting up your Duo Account, please refer to the section First Time Setup for Duo above.

After logging into an SDSU computing service, Duo will ask you to choose an additional authentication method that will require you to take an action on the mobile device you enrolled in Duo. After finishing this, you will be logged in.

Login Failures/Lockouts
Your Duo Token/Account will be disabled automatically when you have five consecutive authentication failures in a row. If you have successful authentication before five failures, the failure count rests to zero. for other reasons that you are not able to login, troubleshooting details are shown below.


  • If you are using "Push" and your phone turns off WiFi when it is locked, unlock your phone and let it connect to the WiFi network before trying to login. The Duo application may get the push request from the cell network, the phone connects to the wireless network and tries to reply over the wireless network and your login may time out.
  • If you are using "push" in an area where there is "free" WiFi where you must click through an agreement to use the network, do that to get full connection or turn off WiFi before you try to log in. Most phones prefer WiFi over the cell network for data. If you are not completely connected to the internet, the Duo application will not be able to talk to the Duo infrastructure to authenticate you.
  • If you are in an area with poor or no cell and WiFi coverage, use a token code instead of typing "push". Start the Duo application and press the key to get the token code. If the service you are connecting to uses "auto push", this won't work for you and you won't be able to log in until you can get a cell or WiFi network. If the service uses auto-push and you will need to use a token to get to it, talk to the administrator of the service to see if push can be turned off.